Added thread pool metrics back to execution flow

hystrix-core/src/main/java/com/netflix/hystrix/AbstractCommand.java

@@ -515,12 +515,14 @@ public void call(Subscriber<? super R> s) {
                     } else {
                         // not timed out so execute
                         try {
+                            threadPool.markThreadExecution();
                             final Action0 endCurrentThread = Hystrix.startCurrentThreadExecutingCommand(getCommandKey());
                             getExecutionObservable().doOnTerminate(new Action0() {
 
                                 @Override
                                 public void call() {
                                     // TODO is this actually the end of the thread?
+                                    threadPool.markThreadCompletion();
                                     executionHook.onThreadComplete(_self);
                                     endCurrentThread.call();
                                 }

hystrix-core/src/test/java/com/netflix/hystrix/HystrixThreadPoolMetricsTest.java

@@ -0,0 +1,69 @@
+package com.netflix.hystrix;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collection;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Copyright 2013 Netflix, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+public class HystrixThreadPoolMetricsTest {
+
+	@Before
+	public void resetAll() {
+		HystrixThreadPoolMetrics.reset();
+	}
+
+	@Test
+	public void shouldYieldNoExecutedTasksOnStartup() throws Exception {
+		//given
+		final Collection<HystrixThreadPoolMetrics> instances = HystrixThreadPoolMetrics.getInstances();
+
+		//then
+		assertEquals(0, instances.size());
+
+	}
+	@Test
+	public void shouldReturnOneExecutedTask() throws Exception {
+		//given
+		final Collection<HystrixThreadPoolMetrics> instances = HystrixThreadPoolMetrics.getInstances();
+
+		//when
+		new NoOpHystrixCommand().execute();
+
+		//then
+		assertEquals(1, instances.size());
+		assertEquals(1, instances.iterator().next().getRollingCountThreadsExecuted());
+	}
+
+	private static class NoOpHystrixCommand extends HystrixCommand<Void> {
+		public NoOpHystrixCommand() {
+			super(
+					Setter.withGroupKey(
+							HystrixCommandGroupKey.Factory.asKey("HystrixThreadPoolMetrics-UnitTest")));
+		}
+
+		@Override
+		protected Void run() throws Exception {
+			return null;
+		}
+	}
+
+
+}